The paper titled "UANM: a platform for experimenting with available bandwidth estimation tools" presented at the IEEE Symposium on Computers and Communications (ISCC 10) in
Riccione (Italy), received the Best Paper Award (Local Category).
The paper is authored by Giuseppe Aceto, Alessio Botta, Antonio Pescapè, Maurizio D’Arienzo (CINI).
The program of the conference is at: http://www.ieee-iscc.org/2010/web_pages/program.html
ELTE's Location Survey
June 2010
Where are the PlanetLab Europe nodes today?
In several research scenarios the geographic location of the measurement nodes plays a significant role. Such information is provided by the site information collection at PlanetLab Central. However, in this collection a relatively large number of the PlanetLab nodes are mislocated, with a varying magnitude of error.
In order to enable more accurate results in this kind of experiment, the Onelab research team at ELTE, led by Prof. Gábor Vattay, has developed a web-based calibration tool to gather reliable information on the location of PlanetLab Europe sites. With the help of the PlanetLab Europe support team at UPMC, all site administrators were asked to correct the geographic position of their PlanetLab nodes. Almost three quarters of the nodes were corrected, and the location of a further 15% of the nodes were approved, making 90% of PlanetLab node locations in Europe correct.
Some nodes had a larger error than the largest distance within Europe! Even though this might seem unreasonable, this was really the case, since some of the nodes were registered to the longitude and latitude coordinates of (0.0) and (1.1).
Thanks to the calibration tool developed at ELTE and the overwhelmingly positive response from site administrators the error in the geolocation coordinates of PlanetLab Europe nodes has been reduced by several orders of magnitude. This development will allow researchers to conduct much more precise geographic experiments on the PlanetLab Europe infrastructure.
Monitoring
April 2010
A video overview of the monitoring capabilities on PlanetLab is now available.
YUM is a software package manager. It is a tool for installing, updating, and removing packages and their dependencies on RPM-based systems. It automatically computes dependencies and figures out what things should occur to install packages. It makes it easier to maintain groups of machines without having to manually update each one using rpm.
A brief video tutorial on using YUM is now available on DailyMotion and YouTube.
6th International workshop on Wireless Network Measurements (Winmee)
April 2010
A paper titled "Performance footprints of heavy users in 3G networks via empirical measurement"will be presented at the 6th International workshop on Wireless Network Measurements (Winmee) 2010, Avignon, France, on May 31st. The paper was authored by Ernst Biersack (Eurecom), Alessio Botta (CINI), Antonio Pescapè (CINI), Stefan Rugel (o2), and Giorgio Ventre (CINI).
Cellular technology is widely used for Internet access, also because most operators are now offering Mbit/s data rates at affordable prices. Many studies analyzed the performance of these networks using analytical or simulation approaches. However, due to lack of data from operational environments, very little is known about the performance of real cellular networks.
In the paper, the authors assess the performance of the 3G network of one of the major European telecom operators, using several recent traffic traces of TCP connections to port 80 and 8080. After presenting global performance statistics related to all the network users, they focus on a specific set of heavy users. To assess their performance and to uncover the related causes, the authors introduce an investigation approach easily repeatable in the very common situation where only data traces are available, with no other information such as mapping of users to cells, network capacity, or packet payload. Analyzing both “single long-lived connections” and “multiple long-lived connections”, they assess the performance of those users, providing insights on how and why performance can vary significantly over time and among different users.
IEEE Symposium on Computers and Communications
April 2010
A paper on network monitoring and measurement will be presented at the IEEE Symposium on Computers and Communications (ISCC) 2010, that will be held in Riccione (Italy), on June 22-25. The paper is authored by Giuseppe Aceto, Alessio Botta, Antonio Pescapè, Maurizio D’Arienzo (CINI).
The paper, titled UANM: a platform for experimenting with available bandwidth estimation
tools, presents UANM (Unified Architecture for Network Measurement), a novel measurement infrastructure for an automatic management of measurement stages, tailored to the end-to-end available bandwidth estimation tools.
The authors describe in details its architecture, illustrating the features they introduced to mitigate the problems affecting available bandwidth estimation in heterogeneous scenarios.
They present an experimental validation in three selected scenarios deployed over a real network testbed: (i) showing how UANM is able to alleviate the interferences among concurrent measures; (ii) quantifying the overhead introduced by the use of UANM; (iii) illustrating how UANM is capable to provide more accurate results thanks to the knowledge of the network environment.
DummyNet Video
April 2010
Luigi Rizzo, Universita` di Pisa, presented a GoogleTechTalk, New Developments in Link Emulation and Packet Scheduling in FreeBSD, Linux, and Windows. In the talk he gives an overview of recent activity done at the Universita` di Pisa on link emulation and packet scheduling.
Rizzo covers two main topics:
- the "dummynet" link emulator shaper, which has been recently ported to Linux and Windows (in addition to FreeBSD and OSX), and extended with support for multiple scheduling algorithms. In the talk we will briefly the features of dummynet, discuss its performance and applicability, and describe the strategy used to build kernel modules for three very different systems starting from the same codebase.
- fast packet scheduling algorithms
He presents QFQ, a truly practical WFQ scheduler with O(1) complexity and very small constants (110ns per packet on a low-end workstation, 2.5..4 times faster than the best competitor). QFQ is available on all major platforms as part of dummynet.
